1. Field of the Invention
The present invention relates to laser equipment employing a light-emitting element made from a material containing an organic mater, and more particularly such a current excitation organic laser oscillator.
2. Related Art
Solid laser has characteristics of high output, high efficiency, high energy storage properties, wide wavelength variable characteristics, and being small, and so the solid layer has a wide application field. Among all, semiconductor laser has main features of being small, lightweight, and having a small threshold value. Semiconductor laser employing inorganic semiconductor had already been developed and put into practice in many fields.
If laser oscillation employing an organic compound is realized, characteristics which cannot be obtained from inorganic semiconductor laser can be given the laser employing an organic compound. The characteristics are the following: for example, flexible laser can be manufactured based on flexibility of a material, a manufacturing process can be simplified, costs can be reduced, and a manufacturing process is diverse (a vapor deposition method, a spin coating method, a printing method, a dip coating method, or the like can be applied), and the like. An outline of laser employing an organic compound material is compiled in a non patent document 1.
As a typical light-emitting element which makes a material containing an organic material emit light, a light-emitting element which emits light by applying an electric field is known. The element is composed of a material containing an organic material interposed between a pair of electrodes, and is formed by stacking functioning layers referred to as a hole transporting layer, a light-emitting layer, and an electron transporting layer. The element emits light by applying voltage between the electrodes to inject electrons and holes to the light-emitting layer. A range of wavelengths of light emission can be varied depending on kinds of materials used for the light-emitting layer or kinds of guest materials to be added.
Non patent document 1: Nir Tessler “quot; Lasers Based on Semiconducting Organic Materials”, Adv. Mater., 1999, 11, p. 363-370
If laser is manufactured by using such the light-emitting element containing an organic material, the laser can be easily enlarged and manufacturing costs can be reduced. Current excitation laser can be easier controlled than light excitation laser, and so whole laser equipment can be downsized.